Typically, excellent impact resistance, excellent transparency, and good environmental stress crack resistance (ESCR, chemical resistance), such as resistance to alcohol and resistance to oil, are required for a material used in the manufacture of medical products. As such medical material, a polyvinyl chloride (PVC)-based resin, a polycarbonate (PC) resin, an acrylonitrile-butadiene-styrene (ABS) resin, a polymethylmethacrylate (PMMA) resin, a polystyrene (PS) resin, or a styrene-acrylonitrile (SAN) resin has been mainly used.
Among these resins, since the PVC-based resin has excellent transparency and chemical resistance as well as excellent flame retardancy, the PVC-based resin has been mainly used in medical products such as needle hubs, patient connectors, and urine containers. However, with respect to the polyvinyl chloride-based resin, since the use of a plasticizer is essentially required, there are human safety issues due to the migration of the plasticizer.
Also, since the polycarbonate resin has excellent transparency and impact resistance but has low ESCR (chemical resistance), cracks may occur due to the effects of residual molding stress when in contact with a cleaner.
Furthermore, since the acrylonitrile-butadiene-styrene (ABS) resin includes an acrylonitrile compound, the ABS resin has excellent ESCR (chemical resistance). However, since the ABS resin is opaque, there is a limitation in using the ABS resin in medical products requiring transparency.
Although the polymethylmethacrylate (PMMA) resin, the polystyrene (PS) resin, and the styrene-acrylonitrile (SAN) resin have excellent transparency, ESCR with respect to alcohol is poor and impact strength is not sufficiently high. Also, since the PS resin and the SAN resin have low impact strength, there is a limitation in using the PS and SAN resins in medical products requiring high environmental stress crack resistance (chemical resistance), impact resistance, and transparency.
Thus, there is a need to develop a resin having high environmental stress crack resistance (chemical resistance) as well as excellent impact resistance and transparency.